1. Field of the Invention
The present invention relates to a touch input apparatus.
2. Description of the Background Art
With the development of information society, various types of requirements for a display device for displaying an image are increasing, and recently, various display devices, such as a Liquid Crystal Display (LCD), a Plasma Display Panel (PDP) and an Organic Light Emitting Diode Display Device (OLED), are being used.
A touch input system enabling a user to easily input information or an instruction may be further included in the display device. The touch input system recognizes a contact between a user's body or an additional input apparatus and the display device, and receives the user's information or the user's instruction. Recently, the additional input apparatus is being used a lot in order to receive a more exact input.
The additional input apparatus mainly uses a method for transferring an electromagnetic signal to the display device. The input apparatus transmits the electromagnetic signal to the display device by using an electromagnetic signal generating circuit, and the display device recognizes the transmitted electromagnetic signal by using an electromagnetic signal receiving circuit such as an antenna. The electromagnetic signal may be decreased or blocked by a peripheral device. Specially, the electromagnetic signal may form an eddy current in a metal plate, and may be decreased in the form of an eddy loss. When the electromagnetic signal is decreased like this, the signal recognition by the display device is weak, and thus the touch sensitivity decreases.